1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * Copyright 2012 Xyratex Technology Limited
4 *
5 * Using hardware provided PCLMULQDQ instruction to accelerate the CRC32
6 * calculation.
7 * CRC32 polynomial:0x04c11db7(BE)/0xEDB88320(LE)
8 * PCLMULQDQ is a new instruction in Intel SSE4.2, the reference can be found
9 * at:
10 * http://www.intel.com/products/processor/manuals/
11 * Intel(R) 64 and IA-32 Architectures Software Developer's Manual
12 * Volume 2B: Instruction Set Reference, N-Z
13 *
14 * Authors: Gregory Prestas <Gregory_Prestas@us.xyratex.com>
15 * Alexander Boyko <Alexander_Boyko@xyratex.com>
16 */
17
18#include <linux/linkage.h>
19
20
21.section .rodata
22.align 16
23/*
24 * [x4*128+32 mod P(x) << 32)]' << 1 = 0x154442bd4
25 * #define CONSTANT_R1 0x154442bd4LL
26 *
27 * [(x4*128-32 mod P(x) << 32)]' << 1 = 0x1c6e41596
28 * #define CONSTANT_R2 0x1c6e41596LL
29 */
30.Lconstant_R2R1:
31 .octa 0x00000001c6e415960000000154442bd4
32/*
33 * [(x128+32 mod P(x) << 32)]' << 1 = 0x1751997d0
34 * #define CONSTANT_R3 0x1751997d0LL
35 *
36 * [(x128-32 mod P(x) << 32)]' << 1 = 0x0ccaa009e
37 * #define CONSTANT_R4 0x0ccaa009eLL
38 */
39.Lconstant_R4R3:
40 .octa 0x00000000ccaa009e00000001751997d0
41/*
42 * [(x64 mod P(x) << 32)]' << 1 = 0x163cd6124
43 * #define CONSTANT_R5 0x163cd6124LL
44 */
45.Lconstant_R5:
46 .octa 0x00000000000000000000000163cd6124
47.Lconstant_mask32:
48 .octa 0x000000000000000000000000FFFFFFFF
49/*
50 * #define CRCPOLY_TRUE_LE_FULL 0x1DB710641LL
51 *
52 * Barrett Reduction constant (u64`) = u` = (x**64 / P(x))` = 0x1F7011641LL
53 * #define CONSTANT_RU 0x1F7011641LL
54 */
55.Lconstant_RUpoly:
56 .octa 0x00000001F701164100000001DB710641
57
58#define CONSTANT %xmm0
59
60#ifdef __x86_64__
61#define BUF %rdi
62#define LEN %rsi
63#define CRC %edx
64#else
65#define BUF %eax
66#define LEN %edx
67#define CRC %ecx
68#endif
69
70
71
72.text
73/**
74 * Calculate crc32
75 * BUF - buffer (16 bytes aligned)
76 * LEN - sizeof buffer (16 bytes aligned), LEN should be grater than 63
77 * CRC - initial crc32
78 * return %eax crc32
79 * uint crc32_pclmul_le_16(unsigned char const *buffer,
80 * size_t len, uint crc32)
81 */
82
83SYM_FUNC_START(crc32_pclmul_le_16) /* buffer and buffer size are 16 bytes aligned */
84 movdqa (BUF), %xmm1
85 movdqa 0x10(BUF), %xmm2
86 movdqa 0x20(BUF), %xmm3
87 movdqa 0x30(BUF), %xmm4
88 movd CRC, CONSTANT
89 pxor CONSTANT, %xmm1
90 sub $0x40, LEN
91 add $0x40, BUF
92 cmp $0x40, LEN
93 jb .Lless_64
94
95#ifdef __x86_64__
96 movdqa .Lconstant_R2R1(%rip), CONSTANT
97#else
98 movdqa .Lconstant_R2R1, CONSTANT
99#endif
100
101.Lloop_64:/* 64 bytes Full cache line folding */
102 prefetchnta 0x40(BUF)
103 movdqa %xmm1, %xmm5
104 movdqa %xmm2, %xmm6
105 movdqa %xmm3, %xmm7
106#ifdef __x86_64__
107 movdqa %xmm4, %xmm8
108#endif
109 pclmulqdq $0x00, CONSTANT, %xmm1
110 pclmulqdq $0x00, CONSTANT, %xmm2
111 pclmulqdq $0x00, CONSTANT, %xmm3
112#ifdef __x86_64__
113 pclmulqdq $0x00, CONSTANT, %xmm4
114#endif
115 pclmulqdq $0x11, CONSTANT, %xmm5
116 pclmulqdq $0x11, CONSTANT, %xmm6
117 pclmulqdq $0x11, CONSTANT, %xmm7
118#ifdef __x86_64__
119 pclmulqdq $0x11, CONSTANT, %xmm8
120#endif
121 pxor %xmm5, %xmm1
122 pxor %xmm6, %xmm2
123 pxor %xmm7, %xmm3
124#ifdef __x86_64__
125 pxor %xmm8, %xmm4
126#else
127 /* xmm8 unsupported for x32 */
128 movdqa %xmm4, %xmm5
129 pclmulqdq $0x00, CONSTANT, %xmm4
130 pclmulqdq $0x11, CONSTANT, %xmm5
131 pxor %xmm5, %xmm4
132#endif
133
134 pxor (BUF), %xmm1
135 pxor 0x10(BUF), %xmm2
136 pxor 0x20(BUF), %xmm3
137 pxor 0x30(BUF), %xmm4
138
139 sub $0x40, LEN
140 add $0x40, BUF
141 cmp $0x40, LEN
142 jge .Lloop_64
143.Lless_64:/* Folding cache line into 128bit */
144#ifdef __x86_64__
145 movdqa .Lconstant_R4R3(%rip), CONSTANT
146#else
147 movdqa .Lconstant_R4R3, CONSTANT
148#endif
149 prefetchnta (BUF)
150
151 movdqa %xmm1, %xmm5
152 pclmulqdq $0x00, CONSTANT, %xmm1
153 pclmulqdq $0x11, CONSTANT, %xmm5
154 pxor %xmm5, %xmm1
155 pxor %xmm2, %xmm1
156
157 movdqa %xmm1, %xmm5
158 pclmulqdq $0x00, CONSTANT, %xmm1
159 pclmulqdq $0x11, CONSTANT, %xmm5
160 pxor %xmm5, %xmm1
161 pxor %xmm3, %xmm1
162
163 movdqa %xmm1, %xmm5
164 pclmulqdq $0x00, CONSTANT, %xmm1
165 pclmulqdq $0x11, CONSTANT, %xmm5
166 pxor %xmm5, %xmm1
167 pxor %xmm4, %xmm1
168
169 cmp $0x10, LEN
170 jb .Lfold_64
171.Lloop_16:/* Folding rest buffer into 128bit */
172 movdqa %xmm1, %xmm5
173 pclmulqdq $0x00, CONSTANT, %xmm1
174 pclmulqdq $0x11, CONSTANT, %xmm5
175 pxor %xmm5, %xmm1
176 pxor (BUF), %xmm1
177 sub $0x10, LEN
178 add $0x10, BUF
179 cmp $0x10, LEN
180 jge .Lloop_16
181
182.Lfold_64:
183 /* perform the last 64 bit fold, also adds 32 zeroes
184 * to the input stream */
185 pclmulqdq $0x01, %xmm1, CONSTANT /* R4 * xmm1.low */
186 psrldq $0x08, %xmm1
187 pxor CONSTANT, %xmm1
188
189 /* final 32-bit fold */
190 movdqa %xmm1, %xmm2
191#ifdef __x86_64__
192 movdqa .Lconstant_R5(%rip), CONSTANT
193 movdqa .Lconstant_mask32(%rip), %xmm3
194#else
195 movdqa .Lconstant_R5, CONSTANT
196 movdqa .Lconstant_mask32, %xmm3
197#endif
198 psrldq $0x04, %xmm2
199 pand %xmm3, %xmm1
200 pclmulqdq $0x00, CONSTANT, %xmm1
201 pxor %xmm2, %xmm1
202
203 /* Finish up with the bit-reversed barrett reduction 64 ==> 32 bits */
204#ifdef __x86_64__
205 movdqa .Lconstant_RUpoly(%rip), CONSTANT
206#else
207 movdqa .Lconstant_RUpoly, CONSTANT
208#endif
209 movdqa %xmm1, %xmm2
210 pand %xmm3, %xmm1
211 pclmulqdq $0x10, CONSTANT, %xmm1
212 pand %xmm3, %xmm1
213 pclmulqdq $0x00, CONSTANT, %xmm1
214 pxor %xmm2, %xmm1
215 pextrd $0x01, %xmm1, %eax
216
217 RET
218SYM_FUNC_END(crc32_pclmul_le_16)
219

source code of linux/arch/x86/crypto/crc32-pclmul_asm.S